Which of the following has a diameter less than its height?

The correct choice regarding having a diameter less than its height is the stand pipe. A stand pipe is a vertical structure that is typically taller than it is wide, reflecting its purpose in holding water above ground level in a narrow, elongated fashion. The design of a stand pipe allows for water storage while maintaining a smaller footprint, making it efficient for specific applications where space may be limited.

Ground storage tanks, elevated storage, and spherical storage generally have a diameter that is equal to or greater than their height. Ground storage tanks are often wide and low-profile, designed for efficient water storage at ground level. Elevated storage tanks are tall structures designed to provide pressure through height, usually resulting in a design where the height exceeds the diameter but not by a significant margin. Spherical storage tanks have a nearly equal diameter and height, as their shape is designed to evenly distribute stress and pressure.

Understanding the physical characteristics and purposes of these storage types reinforces why the stand pipe is the only one among the options that meets the requirement of having a diameter less than its height.